Sofa convertible into bunk bed

ABSTRACT

A sofa bed is convertible to a bunk bed using front and rear links coacting with gas cylinders to lift a bunk frame from the sofa position, in which it is used for seating, to a bunk bed position where seat cushions are used on the bunk and a mattress is available for a lower bunk, being lockable in a down, or seating position and lockable in and up, or bunk bed position with a brace and ladder deployable to secure the bunk.

CLAIM OF PRIORITY

This application claims priority on Provisional application Ser. No. 62/259,956 filed Nov. 26, 2015, having the same title and inventor as the present application and having attorney docket No. CU-72546. This application claims priority on copending application Ser. No. 15/360,791 filed Nov. 23, 2016.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates generally to a furniture assembly, and more particularly, to a sofa bed convertible into a bunk bed having a mechanism being compact and particularly adaptable to placement in vehicles or dimensionally limited locations.

Background

A sofa usually has a seating surface, a back surface, and arms, while a bunk bed has a plurality of sleeping surfaces oriented with at least a portion of a top sleeping surface vertically displaced above a lower sleeping surface. The convertible bunk bed stores the bed in the area above the seating surface. In the prior art EP2110054 (A1) “Mechanism for bunk beds and sofa-bed comprising this mechanism” appears to use curved links to enable a bunk bed to be moved vertically to a position above the lower bed. In the prior art CN202553068 (U) “Novel dual-use sofa” the arms of the sofa are pivoted so that the top bunk is inverted when the sofa is in the seating position and when rotated 180 degrees upwardly so that the frame inverts to present the opposite surface for sleeping.

The former utilizes a mechanism of some complexity for ease of deployment, but lacks a desirable level of rigidity and support when in the bunk bed position. The latter requires a substantial range of motion for movement of significant mass in directions atypical to the user.

In the prior art U.S. Pat. No. 405,495 “Foldable Bunk Bed Assembly” a hinged outer portion of a seat back converts to upper bunk but requires mounting on a wall or bulkhead. U.S. Pat. No. 7,360,261 “Sofa” hinges the seat back to the seat back frame pivoting upward to a bunk bed position. U.S. Pat. No. 4,592,101, “Sofa-bunk bed combination with pivotable cushion” pivots and elevates the seat back to be used as the top bunk. Published application CN202553068U “Novel dual-use sofa” has a hinged front and rear portion with overlapping platforms in which the front portion rotates forwardly and upwardly and inverts, the upper inverted platform forming the bunk bed and the lower platform forming the lower bed. Published application EP2110054 (A1) “Mechanism for bunk beds and sofa-bed comprising this mechanism” uses complex linkage to raise and invert a lower seat platform so that when inverted and fully raised it forms a top bed in a bunk bed.

The present invention solves problems in the prior art described above. The sofa convertible to a bunk bed described herein provides superior sleeping surfaces in a more compact footprint and range of motion, while additionally providing structure for mounting in vehicles and clearance for mounting such securement apparatus as seat belts and harnesses over that of the prior art sofa bunk beds. Links acting in combination with pneumatic cylinders or other telescoping struts provide mechanical advantage and locking for a trussile support mechanism. The frame design additionally incorporates guards and ladders in a unitary assemblage.

Two main embodiments are shown, one with a front link having a pivot carried in a track and a second having fixed pivot for the front link. Each embodiment may have alternative embodiments within the teaching of the main embodiment.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a front elevational view of an embodiment of the sofa convertible to a bunk bed in the bunk bed position.

FIG. 2 is a side elevational view of an embodiment of the sofa convertible to a bunk bed in the bunk bed position.

FIG. 3 a perspective view of an embodiment of the sofa convertible to a bunk bed in the bunk bed position.

FIG. 4 is a front elevational view of an embodiment of the sofa convertible to a bunk bed in the sofa position.

FIG. 5 is a side elevational view of an embodiment of the sofa convertible to a bunk bed in the sofa position.

FIG. 6 is a top plan view of an embodiment of the sofa convertible to a bunk bed with the front guard undeployed.

FIG. 7 is a perspective view of an embodiment of the sofa convertible to a bunk bed in the sofa position.

FIG. 8 is a perspective view of an embodiment of the sofa convertible to a bunk bed in the mid-position.

FIG. 9 is a sectional elevational view of an embodiment of the sofa convertible to a bunk bed in the sofa position.

FIG. 10 is a sectional elevational view of an embodiment of the sofa convertible to a bunk bed in the mid-position.

FIG. 11 is a sectional elevational view of an embodiment of the sofa convertible to a bunk bed in the bunk bed position taken on line A-A of FIG. 1.

FIG. 12 is a perspective view of an embodiment of the sofa with mattress and cushions shown.

FIG. 13 is a perspective view of an embodiment of the sofa with mattress and cushions shown with the bunk configured for sleeping.

FIG. 14 is a perspective view of an embodiment of the sofa back cushion. FIG. 1 is a front elevational view of an embodiment of the sofa convertible to a bunk bed in the bunk bed position.

FIG. 15 is a side sectional view of an embodiment of the sofa taken on line A-A of FIG. 1 having a first alternative track and gas cylinder pivot location.

FIG. 16 is a side sectional view of an embodiment of the sofa taken on line A-A of FIG. 1 having a second alternative track and gas cylinder pivot location.

FIG. 17 is a side elevational view of an embodiment of the sofa taken on line A-A of FIG. 1 having a third alternative track and gas cylinder pivot location.

FIG. 18 is a side elevational view of an embodiment of the sofa taken on line A-A of FIG. 1 having a fourth alternative track and gas cylinder pivot location.

FIG. 19 is a front elevational view of another embodiment of the sofa convertible to a bunk bed in the bunk bed position.

FIG. 20 is a side elevational view of another embodiment of the sofa convertible to a bunk bed in the bunk bed position.

FIG. 21 a perspective view of another embodiment of the sofa convertible to a bunk bed in the bunk bed position.

FIG. 22 is a front elevational view of another embodiment of the sofa convertible to a bunk bed in the sofa position.

FIG. 23 is a side elevational view of another embodiment of the sofa convertible to a bunk bed in the sofa position.

FIG. 24 is a top plan view of an embodiment of the sofa convertible to a bunk bed with the front guard undeployed.

FIG. 25 is a perspective view of an embodiment of the sofa convertible to a bunk bed in the sofa position.

FIG. 26 is a perspective view of an embodiment of the sofa convertible to a bunk bed in the mid-position.

FIG. 27 is a sectional elevational view of an embodiment of the sofa convertible to a bunk bed in the sofa position, taken on line A-A of FIG. 19.

FIG. 28 is a sectional elevational view of an embodiment of the sofa convertible to a bunk bed in the mid-position.

FIG. 29 is a sectional elevational view of an embodiment of the sofa convertible to a bunk bed in the bunk bed position taken on line B-B of FIG. 19.

FIG. 30 is a fragmentary perspective view of the left side linkage assembly, looking from the rear towards the front.

FIG. 31 is a fragmentary perspective view of the right side linkage assembly, looking from the rear towards the front.

FIG. 32 is a sectional view of a powered variation on an alternative embodiment.

FIG. 33 is a fragmentary sectional view of a lock mechanism

FIG. 34 is a perspective view of an embodiment in the bunk bed position.

Terms such as front, side, rear, left and right as may be used herein are relative terms referring to the sofa convertible to a bunk bed and are not limited to its mounting, installation or arrangement to any particular position or space in a room or vehicle or to which direction a person is oriented on the sofa or bed. Unless otherwise qualified left and right refer to the point of view of a person sitting on the sofa.

DETAILED DESCRIPTION

Referring to the drawings, the sofa bed 10 of this invention is generally shown. The sofa bed 10 includes base frame assembly 12 with side frames 14 and 16 interconnected by rear transverse frame 18 and front transverse frame 20. Side frames 14 and 16 may be formed of perimetrical frame members, solid plates 22, 24, or a combination. Each plate 22, 24 is formed and arranged so as to have an angled, straight tracks or guide slots 26, 28.

Advantages to using solid sheet or plate could include the substantial elimination of components requiring assembly; the ability to be formed through automated manufacturing means such as laser cutting or other appropriate machining, and the elimination of braces between the tracks or guide slots 26, 28 which can be more easily maintained in position by the presence of the solid web between them.

The upper bunk frame 30 is formed with a lower perimetrical frame 32 and a rear guardrail assembly 34. On each side is a side guard 36, 38.

Upper bunk frame 30, when deployed in the bunk bed position is primarily supported by right and left front links 40, 42 and right and left rear links 44, 46. The right and left front links 40, 42 are dynamically actuated and statically fixed (when locked) by right and left front cylinders, 48, 50. The right and left rear links 44, 46 are dynamically actuated and statically fixed (when locked) by right and left rear cylinders, 52, 54. Cylinders 48, 50, 52, 54 are preferably pneumatic cylinders but equivalents such as hydraulic cylinders, or spring, screw or rack and pinion mechanisms could be used to perform the function of assisting in raising bunk bed frame 30 and maintaining it in the bunk bed position 56.

Front brace and ladder assembly 60 is pivotally mounted to the front frame In the bunk bed position 56 ladder 58 is rotated to a vertical position and locked, front brace 60 is rotated to a vertical position and locked with locking mechanism 64. Front guard 62 is rotated to a vertical position and locked with locking mechanism 64. Extending upwardly from side frames 14 and 16 are tabs 66, 68. These may be formed with frame members or plate or a combination.

In an embodiment, here described with reference to left links 42, 46 and cylinders 50, 54, which are shown in the sectional views of FIG. 10, 11 and 12, left front link 42 has a top pivot 70 and bottom pivot 72. Left rear link 46 has a top pivot 74 and a bottom pivot 76. Left front cylinder 48 has an upper pivot which is connected to the corresponding link and a lower cylinder pivot 82. Left rear cylinder 54 has an upper pivot 84 and a lower pivot 84. The relative terms top, bottom, upper and lower refer to the orientation of the components when in the bunk bed position.

Front link bottom pivot 72 is formed and arranged to slide in guide slot 28 thereby providing the range of motion needed to permit the upper bunk frame 30 to move vertically, while also remaining in a substantially horizontal orientation. Rear link bottom pivot 76 is mounted to tab 68 in a fixed location so as to permit link 46 to rotate about pivot 76. Front link top pivot 70 and rear link top pivot 74 are mounted in fixed front and rear locations on upper bunk frame 30.

Left front cylinder 48 is mounted with front cylinder lower pivot 82 in a fixed location on plate 22 and the front cylinder upper pivot connected at front link bottom pivot 72. As pivot 72 slides in angled slot 28, pivot 82 causes compression of cylinder 48. However, as bunk frame 30 is moved first upwardly and frontwardly and then continuing upwardly and rearwardly, cylinder 48 extends to aid in raising frame 30 to the bunk bed position 56. This movement works together with rear cylinder 52 and rear link 44 through mounting rear cylinder lower pivot 86 on tab 66 with rear cylinder upper pivot 84 mounted to the median portion of rear link 44. These references refer to the sectional views and the opposite side will be a mirror image of that shown and described.

As frame 30 is moved from the sofa position toward the mid position, left rear cylinder 54 compresses slightly, but as link 46 passes the axis of cylinder 54, then cylinder 54 urges link 46 upward toward bunk bed position 56. In bunk bed position 56 each of right and left front cylinders, 48, 50 and right and left rear cylinders, 52, and 54 may be locked. At this time the ladder 58 and brace 60 are also locked at lock mechanisms 64. The bed is converted to a sofa in substantially the reverse manner.

The geometry of links right and left front links 40, 42, right and left rear links 44, 46 and their respective front link top pivot 70 front link bottom pivot 72, rear link top pivot 74 , rear link bottom pivot 76, front cylinder upper pivot 80, front cylinder lower pivot 82, rear cylinder upper pivot 84 and rear cylinder lower pivot 86 is such that manual deployment may be accomplished as described, while alternative cylinders and other actuators and controls could be utilized for automatic deployment.

The mattress 90 shown in FIGS. 3, 11, 12 and 13 and the cushions shown in FIGS. 12 and 13 can advantageously be arranged so that the mattress 90 remains in the same position, either under the frame 30 when in the sofa position or available for sleeping in the bunk bed position 56. Seat cushion 92 may be thick enough to serve as a top mattress on the top bunk, or seat back cushion 94 could be formed in a foldable manner and unfolded from the sofa seat back configuration to a sleeping configuration. Cushion 92 could remain and be combined with cushion 94 for double the thickness.

In the alternative embodiments shown in FIGS. 15, 16, 17 and 18 sectional views at section A-A of FIG. 1, different configurations of tracks and links provide properties that may be tailored to specifically desired performance relative to the movement, compactness, strength and mechanical rigidity, noting sofa bed 10 right side frame 14 solid plates 22 guide slot 28 right front link 40 right rear link 44, right front cylinders 48 and right rear cylinder, 54 generally formed and arranged as described above but with specific variations controlling the movement of the bunk bed assembly as it is raised and lowered. In FIG. 15 and FIG. 16 slot 28 has a lower straight portion, a forwardly curving intermediate portion and an upwardly curving upward portion. FIG. 16 has increased size component sections and reinforcing members on plate 22. FIGS. 17 and 18 have some of the components removed for clarity, but show slot 28 in different configurations. FIG. 17 shows slot 28 in a nearly vertical orientation, with a generally straight lower portion an intermediate curve and a generally straight upward portion. In FIG. 18 slot 28 has a near vertical lower portion a forwardly curving intermediate portion and a straight upper portion.

Two main embodiments are shown, one with a front link having a pivot carried in a track and a second having fixed pivot for the front link. In the second embodiment front and rear links each have a lower pivot fixed on the side frame.

In the embodiment illustrated in FIG. 19-22 sofa bed 10 has a base frame assembly 212 formed with side frames 214 and 216 interconnecting rear transverse frame 218 and front transverse frame 220. Side frames 214, 216 have rear pivot mounting members 222, 224 positioned near the rear and front pivot mounting members 226, 228 positioned near the front.

Upper bunk assembly 230 including perimetrical frame 232 has top rear guardrail assembly 234 projecting upwardly from the rear and top side frames 236, 238 at the side forming a bunk enclosed on the sides and rear, but with the front open when in the lowered, seating, position,

Pivotally connected to front pivot mounting members 226, 228 right and left front links 240, 242. Similarly, pivotally connected to pivot mounting members 222, 224 are right and left rear links 244, 246.

In the down, or seating position, the bunk bed frame 230 is secured to the base frame 212 through the interaction of a lock assembly. In the embodiment show, lock plate 248, engaged with lock plunger 250 engaging an aperture in plate 248. Plate 248 is angled such that engagement of plunger 250 is essentially perpendicular to plate 248 and to the direction of motion of the frame 230 as it is raised. Plunger 250 can be cable actuated being interconnected to lock release 251. Release 251 could be manually operated, pedal operated, electrically, pneumatically or hydraulically operated. Manual operation has advantages in the use of fewer and generally more reliable parts. Electrical operation, such as by a solenoid has advantages in the variable means for control whether by switch or data processing controller.

After release 251 is actuated, plunger 250 disengages plate 248 thereby permitting upper bunk frame 230 to be lifted with the assistance of right and left gas cylinders, 252, 254 to bunk bed position 256.

Ladder 258 is, in this embodiment, part of the right side of front brace frame 260. Frame 260 thus, has one ladder post at the right side and another post at the left side. Frame 260 is pivotally mounted to frame 212 so that it folds flat above mattress 290. When bunk frame 230 is fully raised, frame 260 is deployed to as to latch to frame 260 thereby providing fixed vertical support.

Front guard 262 is pivotally mounted to the front of frame 230 so that it can be stowed underneath when frame 230 is moved to and is in the sitting position, but can be rotated through substantially 270 degrees to provide a total of four guards around the perimeter of frame 230.

In particular, front link mounting strut 263 depends downwardly from frame 230 and in addition to providing structure to which front links 240, 242 are pivotally connected (there is a mounting strut 262 on each side of frame 230) additionally is structurally supportive of plate 248 and ladder locking mechanism 264. Mechanism 264 I the embodiment uses projecting ladder locking tabs 266 which receive frame rod 268. Other locking or other engagement mechanisms could also be used.

The movement of assembly 230 using links 240, 242, 244 and 245 is controlled as bunk 230 moves slightly frontwardly and upwardly and then slightly rearwardly into a substantially vertically inline location above frame 212. This is accomplished as links 240, 242, rotate around front link top pivot 270 and front link bottom pivot 272 and links 244, 245 rotate around rear link top pivot 274 and rear link bottom pivot 276.

Movement is additionally controlled by links 240, 242, 244 and 245 having front timing arms 278, 279 and rear timing arms 280, 281 projecting downwardly, and generally perpendicularly although at a slightly obtuse angle. Arms 278, 279, 280 and 281 are themselves interconnected by timing links 282 283 that coordinate the rotation of links 240, 242, 244 and 245 as bunk 230 is raised or lowered.

The interconnection links 240, 242, 244 and 245, arms 278, 279, 280, 281 timing links 282 283 and pivots 270, 272, 274 and 276 enables the use of cylinders 252, 254 connected at cylinder upper pivot 284 and cylinder lower pivot 286 (each side having said pivots) so as to urge bunk 230 upwardly and permit downward movement for stowing in the seating position.

Thus, a single gas cylinder 252, 254 on each side directly urges the rear link 244, 246 upward while resisting closing from a bunk position 256 to a seating position and the timing link and pivot arrangement transfers those forces to the entire linkage arrangement. Each link 244, 246 has a top pivot 274 (hidden in FIG. 28) the rear link top pivot 274 connected directly to the bunk 230 using appropriate reinforcement and mounting members.

The front link 240, 242 is connected to a front strut 260 depending downwardly from the bunk frame 230. Strut 263 may be advantageously mounted in cooperation with components enabling both upward locking of brace frame 260 at locking mechanism 264 and incorporating downward locking such as lock plate 248.

Each of the front 240, 242 and rear 244, 246 links has a timing connection arm 278, 279, 280, 281 and the front 278, 279 and rear 280, 281 timing connection arms are interconnected by a timing link 282, 283. As shown in FIG. 30, 31, fragmentary perspective views looking from the back toward the front at each back corner. Looking forwardly side frames 216, 214 support the lower portion of the linkage mechanism showing left and right rear links 246, 244 and left right front links 242, 240, pivotally mounted at front link bottom pivot 272L, 272R and rear link bottom pivot 276 L, 276 R respectively. It will be noted that rear links 244, 246 can be advantageously formed from channel thereby permitting left right and gas cylinders, 254, 252 to be mounted within the flanges of the channel. Additionally, timing arms 278, 279, 280, 281 can be similarly formed, permitting the outer flanges to abut timing link, 283, 282 while the inner flanges permit spacing for timing link pivots 283 P, 282 P thereby providing clearance for operation while providing a more broad bearing arrangement for pivots 283 P, 282 P. Pivot mounting members 222, 224, 226, 228 can be configured as generally “U” shaped brackets providing similarly spaced bearing surfaces for the respective pivots they receive. A crossbar 296 interconnects the ends of left and right rear links 246, 244. At the bottom of side frames 214, 216 appropriate members could be included such as flanges or braces 299 for mounting to a floor or deck.

Electric motor actuation could also be used as shown in FIG. 32. An electric motor 312 could drive cables 314, 316 that operate a threaded thrust assembly 318, 320 or a rack arrangement that moves thrust member 322 which bears on arms 278, 279.

FIG. 34 shows an upholstered sofa 10 in bunk bed configuration. Right and left side frames 214 and 216 are upholstered as are top side frames 236, 238. Top rear guardrail assembly 234 is covered and can receive removable seat back cushions which provide back support when in the seating position, with greater sleep area when removed. Seat cushions 292 can function as a sleep surface or they could be replaced with a stored mattress. The platform which supports the seat cushions and mattress could be formed with grid systems, convoluted springs hybrid grid and coil systems or springs such as are taught in U.S. Pat. No. 9,103,397 the disclosure of which is incorporated by reference as if fully set forth herein. 

In accordance with the invention it is claimed:
 1. A sofa bed convertible into a bunk bed has a base frame assembly formed with side frames interconnecting a rear transverse frame and a front transverse frame, said base frame having a front and a back thereby respectively defining a front and rear of said frame assembly; said side frames have lower rear pivot mounting members positioned near the rear and lower front pivot mounting members positioned near the front of said side frames; an upper bunk including a perimetrical frame has a bunk side frames and a top rear guardrail assembly projecting upwardly from said perimetrical frame and interconnecting said rear and top side frames, thereby forming a bunk enclosed on the sides and rear, but with the front open when in a lowered, seating, position; said lower front pivot mounting members pivotally connect to a front link and said lower rear pivot mounting members pivotally connect to a rear link at the respective bottom link pivots of each front and rear link; said bottom link pivots lie in different horizontal planes; said upper bunk frame having placed thereon a front pivot mounting strut with an upper front pivot mount thereon and a rear pivot mount said upper pivot being pivotally connected to said front link and said rear pivot being pivotally connected to said rear link; said upper link pivots lie in different horizontal planes; each of said front and rear links having a timing arm depending from said links proximate said bottom link pivots, such that said arms depend substantially vertically downwardly when said sofa has said bunk in a lowered position; a timing link pivotally interconnecting said arms to one another; said bunk being movable from said lowered position to an upper bunk bed position through movement controlled by said front, rear and timing links such that said bunk remains in a substantially horizontal position through its range of motion.
 2. The sofa of claim 1 further comprising: movement of said bunk through operative interconnection of said links is controlled as said bunk moves from said lower position, slightly frontwardly and upwardly and then after passing a crest of forward movement, slightly rearwardly into a substantially vertically inline location above said frame at said upper position, through said front links rotating around said front link top pivot and said front link bottom pivot in time with said rear links rotating around said rear link top pivot and said rear link bottom pivot, said timing being additionally controlled by said front and rear links having said respective front and rear timing arms projecting downwardly, and generally perpendicularly at a slightly obtuse angle to said front and rear links, said arms being themselves interconnected by said timing links to coordinate the rotation of said front and rear links as said bunk is raised or lowered.
 3. The sofa of claim 2 further comprising: said pivotally connected front, rear and timing links and arms, comprising a linkage in which a cylinder is connected at a cylinder upper to said rear link and a cylinder lower pivot at said lower side frame so as to urge said bunk upwardly and permit downward movement for stowing in a seating position said urging exerted by directly urging the rear link upward as the bunk is moved in that direction while resisting closing from a bunk position to a seating position by weight or imparted force, whereby said timing link and pivot arrangement transfers forces to the entire linkage.
 4. The sofa of claim 2 further comprising: mechanical advantage is deploying said bunk from a sitting position to a bunk bed position, and resisting forces tending to impart lowering from said bunk bed position to said sitting position is accomplished by a mechanical apparatus bearing on said linkage comprising one of pneumatic cylinders, electric motors and power transmission; hydraulic motors and power transmission; cable operation.
 5. The sofa of claim 2 further comprising: a pivoting brace and ladder assembly being mounted so as to substantially span said side frames and rest in a folded position when said bunk is in a sofa position and to deploy upwardly to support said bunk in a bunk bed position.
 6. The sofa of claim 2 further comprising: said front link is connected to a front strut depending downwardly from a bunk frame; said strut being mounted to permit cooperation with components enabling both upward locking of said bunk frame by said brace and ladder assembly at a latching mechanism and incorporating downward locking such as lock plate which engages a lock plunger in a downward locking position; said plunger is manually or automatically engageable and disengageable.
 7. The sofa of claim 1 further comprising: front and rear timing connection arms are interconnected by a timing link; said side frames support a lower portion of a linkage mechanism with rear and front links pivotally mounted at a front link bottom pivot and a rear link bottom pivot respectively; said rear links are formed and arranged to permit gas cylinders to be recess mounted within the link structure; said timing arms are formed and arranged so as to permit a first member to abut said timing link and a second member to permit spacing for timing link pivots thereby providing clearance for operation while providing a more broad bearing arrangement for said pivots; pivot mounts being formed and arranged so as to provide spaced bearing surfaces for the respective pivots they receive; a crossbar interconnecting the ends of left and right rear links.
 8. The sofa of claim 5 further comprising: said bunk bed frame is secured to said base frame through the interaction of said lock assembly in which said lock plate engages said lock plunger by said plunger engaging an aperture in said plate and in which said plate is angled such that engagement of said plunger is essentially perpendicular to plate and to the direction of motion of said bunk as it is raised said interaction accomplishing said release action by, after a release control is actuated, said plunger disengages said aperture thereby permitting said bunk to be lifted with the assistance of a mechanical advantage mechanism to said bunk bed position.
 9. The sofa of claim 8 further comprising: said plunger is operated by one of cable actuation being interconnected to a manually operated lock release, cable actuation being interconnected to pedal operated lock release, an electrically actuated lock release, a pneumatically actuated lock release or a hydraulically actuated lock release.
 10. The sofa of claim 5 further comprising: a front guard is pivotally mounted to the front of said bunk frame so that said guard can be stowed underneath when said bunk is moved to and is in the sitting position, but can be rotated through substantially 270 degrees so that, in combination with side and rear guards a total of four guards extends around the perimeter of said bunk frame enclosing it on three edges and substantially enclosing on the fourth.
 11. A sofa convertible into bunk bed comprising: a base frame assembly having a side frame; an upper bunk frame; a front link and a rear link rotatably connecting the base frame to the upper bunk frame such that the upper bunk frame elevates between a bunk bed position and a sofa position, wherein the front link and the rear link rotatably connect the base frame to the upper bunk frame such that the upper bunk frame moves vertically while also remaining in a substantially horizontal orientation when the upper bunk frame elevates between the bunk bed position and the sofa position; the front link includes a top pivot connected to the upper bunk frame and a bottom pivot connected to the side frame; and the rear link includes a top pivot connected to the upper bunk frame and a bottom pivot connected to the side frame; a rear cylinder including an upper pivot pivotally connected to a median portion of the rear link and a lower pivot pivotally connected to a fixed location on the side frame.
 12. The sofa convertible into bunk bed of claim 11, further comprising: a ladder rotatably connected to the base frame and configured to be rotated to a vertical position and locked; a front brace connected to the ladder and configured to be rotated to a vertical position and in conjunction with said ladder, and being locked with a locking mechanism.
 13. The sofa convertible into bunk bed of claim 12, wherein: the ladder rests over an upper portion of the base frame when in the sofa position, and rotates in a first direction to the vertical position; a front guard mounted to said upper bunk frame so as to be stowable underneath said upper bunk frame and deployed outwardly and thence upwardly to lock in a vertical position; said front guard rotates towards a second direction opposite the first direction.
 14. The sofa convertible into bunk bed of claim 13, further comprising a mattress positioned on the base frame; and one or more cushions positioned on the upper bunk frame, wherein the mattress and the cushions are arranged such that the mattress remains in the same position when the upper bunk frame is in the bunk bed position and the sofa position.
 15. A sofa convertible into bunk bed comprising: a base frame assembly having a side frame, the side frame having a pivot mount; an upper bunk frame; a front link and a rear link rotatably connecting the base frame to the upper bunk frame such that the upper bunk frame elevates between a bunk bed position and a sofa position; wherein the front link includes a top pivot pivotally connected to the upper bunk frame and a bottom pivot pivotally connected to the side frame; the rear link includes a top pivot pivotally connected to the upper bunk frame and a bottom pivot pivotally connected to the side frame.
 16. The sofa convertible into bunk bed of claim 15 further comprising: a rear cylinder including an upper pivot pivotally connected to a median portion of the rear link and a lower pivot pivotally connected to a fixed location on the side frame.
 17. The sofa convertible into bunk bed of claim 16 further comprising: a ladder rotatably connected to the base frame and configured to be rotated to a vertical position and locked; a front brace connected to the ladder and configured to be rotated to a vertical position and locked with a locking mechanism.
 18. The sofa convertible into bunk bed of claim 15 further comprising: Force is imparted to move said bunk bed from a sitting position to a bunk bed position and to resist lowering, by one of gas cylinders, electric motor and power transmission; cable actuation.
 19. The sofa convertible into bunk bed of claim 17 further comprising: a lock mechanism for positively locking said bunk in a sitting position; a latch mechanism for latching said ladder and brace in a bunk bed position.
 20. The sofa convertible into bunk bed of claim 19 further comprising: said lock mechanism can be actuated by one of cable operated manual control, cable operated pedal control, electrical control, pneumatic control or hydraulic control. 